使用LINQ将项目推入堆栈 [英] Pushing Items into stack with LINQ

问题描述

我如何以编程方式将字符串数组推入通用堆栈?

How can i programatically push an array of strings into generic Stack ?

字符串数组

 string[] array=new string[]{"Liza","Ana","Sandra","Diya"};

堆栈设置

 public class stack<T>
 {
    private int index;

    List<T> list; 

    public stack()
    {
        list = new List<T>();
        index=-1;

    }

    public void Push(T obj)
    {

        list.Add(obj);
        index++;
    }
 ...........
}

我需要在这里做些什么更改?

stack<string> slist = new stack<string>();
var v = from vals in array select (p => slist.Push(p));

错误报告:

The type of the expression in the select clause is incorrect.

推荐答案

LINQ是一种查询语言/框架.您要在此处执行的是对集合对象的修改，而不是查询(选择)-这肯定不是LINQ设计(甚至能够)的 not

LINQ is a query language/framework. What you want to perform here is a modification to a collection object rather than a query (selection) - this is certainly not what LINQ is designed for (or even capable of).

但是，您可能想为Stack<T>类定义一个扩展方法.请注意，在这里使用BCL Stack<T>类型(正是您所需要的)也是有意义的，而不是使用List<T>重新发明轮子.

What you might like to do, however, is to define an extension method that for the Stack<T> class, however. Note that it also makes sense to here to use the BCL Stack<T> type, which is exactly what you need, instead of reinventing the wheel using List<T>.

public static void PushRange<T>(this Stack<T> source, IEnumerable<T> collection)
{
    foreach (var item in collection)
        source.Push(item);
}

然后允许您执行以下操作:

Which would then allow you do the following:

myStack.PushRange(myCollection);

如果您还没有确信，那么还有另一个哲学原因:LINQ的创建是为了将功能性范例引入C#/.NET，而功能性编程的核心是无副作用的代码.因此，将LINQ与状态修改代码结合在一起将非常不一致.

And if you're not already convinced, another philosophical reason: LINQ was created to bring functional paradigms to C#/.NET, and at the core of functional programming is side-effect free code. Combining LINQ with state-modifying code would thus be quite inconsistent.

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